It is common knowledge that 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(2-nitrophenyl)-1,4-dihydropyrine (preparation Niphedipin) cf. W. Vater et al. Pharmacology of dimethyl ester of 4-(2'-nitrophenyl)-2,6dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid. Arzneimittel-Forschung, 1972, Bd. 22 (1), S.1/ and 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(2-difluoromethoxyphenyl)-1,4-dihydro pyridine (cf. USSR Inventor's Certificate No. 706,410, Cl. C 07 D 211/90, A 61 K 31/44, 1979). The medicinal preparations mentioned above are highly toxic. In addition, Niphedipin is occasionally causative of dizziness and nausea and is a light-instable drug.
Known in the art is also 2,6-dimethyl-3-methoxy-carbonyl-4-(3-nitrophenyl)-5-[2(N-benzyl-N-methylam ino) ethoxycarbonyl]-1,4-dihydropyridine hydrochloride (preparation Nicardipin), possessing vasodilation activity preponderantly towards cerebral vessels (cf. Takenaka T. Usuda S., Nomura T., Maeno H., Sado T., Arzneimittel-Forschung, 1976, Bd. 26, No. 12, S. 2172-2178).
The aforesaid compound is featured by inadequate activity and a very complicated process for its production.
The compounds disclosed in the invention are novel and have not so far been described in literature.
The invention has for its object to provide novel compounds capable of producing high hypotensive and vasodilation effects being at the same time of low toxicity.